This invention relates to data gathering systems for obtaining real time measurements of a number of different variables normally measured in molten metal processes, such as the steel making process. These variables include the temperature of the steel, its carbon content, its oxygen content, its aluminum content; as well as the manganese, magnesium and silicon content and the carbon equivalent. Measurements of this type, in molten metal baths, in industrial surroundings, have been made for a number of years using hard wired connections between the primary element or sensor which detects the magnitude of the variable being measured and the instrument being used to display or record the magnitude of the variable.
Typical of such measurements is the measurement of temperature in molten steel by the use of platinum thermocouples mounted at the end of a lance which serves to immerse the thermocouple either manually or automatically into the molten steel. Such thermocouples are usually housed in a protecting case which melts upon immersion to allow exposure of the couple to the molten steel so that the couple will develop an output potential which is directly related to the temperature of the steel. When the primary element is a thermocouple, the connection to the indicating or recording instrument is usually by way of compensating leadwire, as is well known in the thermocouple art.
In many molten metal applications where it is desired to make measurements by automatically immersing sensors into the molten metal, the use of hard wired connections becomes a source of many problems. Workers working at sites using such automatic systems have found that they occasionally trip on the wires and that the wires become damaged to such an extent that they miss important readings. In addition to the disadvantage occasioned by the missed readings, there is added disadvantage which results from the maintenance required to repair the damaged wires. In those applications where it may not be necessary to use an automatically operated lance for immersion hard wired connections are still found to be an inconvenience in operating such a device.
It is an object of this invention to provide a data gathering system which will allow the indicating and recording of the magnitude of both a single variable as well as a plurality of variables in molten metal processes in such a way as to avoid the inconvenience and costly maintenance involved in hard wired systems such as have been used in the past.